1. Field of the Invention
The present invention relates to a DNA chip, more particularly, to a DNA chip achieving precise DNA analysis, a DNA chip kit, and a method of manufacturing the DNA chip.
2. Description of the Related Art
Biochips may be biological microchips in which biomolecules, e.g., DNAs, proteins, etc., may be immobilized on small substrates and may be used to analyze genetic defects, protein distribution, reaction patterns, etc. In recent years, with the advance of genome projects, the genomic nucleotide sequences of various organisms have been identified. Thus, there has been an increasing interest in microchips, i.e., DNA microchips, for analyzing the DNA of an organism.
DNA microchips may be immobilized with multiple single-stranded cDNA probes or oligonucleotide probes. The type and quantity of probes to be immobilized may be changed according to the specific application of the DNA microchips.
When target analytes labeled with a labeling agent, e.g., a fluorescent substance, etc., are applied to DNA chips, complementary hybridization may occur. Once hybridization is accomplished, the labeling agent may be left on the DNA microchips even after the DNA microchips are washed. Thus, when the DNA microchips are exposed to light, fluorescent light having a predetermined wavelength may be emitted from the labeling agent of the DNA chips. The emitted fluorescent light may be analyzed by a photodetector to determine the occurrence and degree of hybridization.
However, when the DNA chips are exposed to light after hybridization, an excitation light for exciting the labeling agent may be diffusedly reflected from the chip substrates, or any light that does not contribute to the excitation of the labeling agent may be reflected from the chip substrates, thereby resulting in an interference between the reflected light and normal fluorescent light. The light interference may appear as signal noise, i.e., a reduced intensity of fluorescent light emission, which may make it difficult to achieve precise DNA analysis, thereby leading to a reduction in the reliability of the DNA analysis.